What about Norfloxacin (fluoroquinolone antibiotic)?

From the Guidelines

Norfloxacin should be reserved as an alternative treatment for urinary tract infections only when other UTI agents cannot be used, due to the increasing concern of fluoroquinolone resistance and its potential impact on morbidity, mortality, and quality of life. The typical adult dosage of norfloxacin is 400 mg taken orally twice daily for 3-10 days, depending on the infection being treated. For uncomplicated urinary tract infections, a 3-day course is often sufficient, while complicated infections may require 7-10 days of treatment 1. Norfloxacin works by inhibiting bacterial DNA gyrase and topoisomerase IV, enzymes essential for bacterial DNA replication, thereby preventing bacterial growth and reproduction.

When taking norfloxacin, it should be administered with a full glass of water on an empty stomach, either 1 hour before or 2 hours after meals, as food can reduce its absorption. Patients should avoid antacids, iron, zinc, and calcium supplements within 2 hours of taking norfloxacin as these can significantly reduce the drug's effectiveness. Common side effects include nausea, headache, and dizziness. More serious concerns include tendon inflammation or rupture, peripheral neuropathy, and central nervous system effects, particularly in elderly patients. Norfloxacin is contraindicated in patients with known hypersensitivity to fluoroquinolones and should be used cautiously in patients with kidney disease, seizure disorders, or myasthenia gravis.

Some key points to consider when prescribing norfloxacin include:

• The increasing resistance of fluoroquinolones among community uropathogens, which may mitigate the usefulness of this antimicrobial class 1
• The potential for fluoroquinolone use to promote resistance, not only among uropathogens but also other organisms, causing more serious and difficult-to-treat infections at other sites 1
• The association between fluoroquinolone use and increased rates of MRSA 1
• The recommendation to reserve fluoroquinolones, including norfloxacin, as an alternative only when other UTI agents cannot be used 1

It is essential to weigh the benefits and risks of norfloxacin use, considering the potential for resistance and serious side effects, and to prioritize alternative treatments when possible. The most recent guidelines recommend sulfamethoxazole-trimethoprim, nitrofurantoin, and fosfomycin as first-line treatments for uncomplicated urinary tract infections, with fluoroquinolones, including norfloxacin, reserved for alternative use 1.

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Norfloxacin Overview

• Norfloxacin is a fluorinated quinolinecarboxylic acid with potent antibacterial activity against aerobic, gram-negative bacteria, including Enterobacteriaceae, gentamicin-resistant Pseudomonas aeruginosa, and penicillin-resistant Neisseria gonorrhoeae 2.
• It exhibits good activity against methicillin-resistant and -sensitive Staphylococcus aureus, but less activity against most other aerobic, gram-positive organisms, and anaerobic bacteria are resistant to the drug 2.

Pharmacokinetic Properties

• The pharmacokinetic properties of norfloxacin after a 400-mg oral dose consist of a peak serum concentration of 1.3-1.58 micrograms/ml, an elimination half-life of 3-7 hours, and good penetration into kidney and prostatic tissues 2.
• Renal excretion is the major route of elimination 2.

Clinical Use

• Norfloxacin is highly effective in the treatment of uncomplicated and complicated urinary tract infections, and gonococcal urethritis 2.
• It has been shown to be effective in the treatment of lower urinary tract infections, with bacteriological eradication achieved in more than 90% of patients 3.
• Short-term therapy (3 days) with norfloxacin has been shown to be as effective and tolerable as a 10- to 14-day conventional therapeutic schedule in the treatment of lower uncomplicated UTIs 3.

Treatment Duration and Efficacy

• A study comparing single-dose norfloxacin therapy with 3-day therapy found that 3-day therapy was more effective in the treatment of uncomplicated urinary tract infections in women 4.
• Another study found that norfloxacin 800 mg once-daily was as effective and safe as norfloxacin 400 mg twice-daily in the treatment of uncomplicated urinary tract infections in women 5.
• A double-blind comparison of 3-day versus 7-day treatment with norfloxacin found that the accumulated efficacy was higher in the 7-day treatment group, but the median time to disappearance of symptoms was the same in both groups 6.

Adverse Effects

• Adverse effects of norfloxacin are generally well tolerated and usually do not require discontinuation of therapy 2.
• The overall incidence of drug-related adverse experiences has been reported to be around 2.3% 3.
• Adverse events have been reported in around 14.0% of patients receiving norfloxacin 800 mg once-daily and 9.6% of patients receiving norfloxacin 400 mg twice-daily 5.